diff --git a/boards/cc2650stk/board.c b/boards/cc2650stk/board.c
index fcbeb8d96ede174c544882f2856c2c20d773b51a..08fba344538242b31b1d1c2bdd270598d1af6f38 100644
--- a/boards/cc2650stk/board.c
+++ b/boards/cc2650stk/board.c
@@ -21,7 +21,7 @@
 #include "board.h"
 
 /**
- * @brief           initialise the board
+ * @brief           initialize the board
  */
 void board_init(void)
 {
diff --git a/cpu/mips32r2_common/cpu.c b/cpu/mips32r2_common/cpu.c
index 1676212d8739fd4c4f4f6e0706327e44870ea6ad..2c1a204aee1e6835ddc2ec382eb672d0b90668a5 100644
--- a/cpu/mips32r2_common/cpu.c
+++ b/cpu/mips32r2_common/cpu.c
@@ -43,7 +43,7 @@ extern char _edata __attribute__((section("data")));
 void software_init_hook(void)
 {
 #ifdef FLASH_XIP
-    /* copy initialised data from its LMA to VMA */
+    /* copy initialized data from its LMA to VMA */
     memcpy(&_fdata, &_rom_data_copy, (int)&_edata - (int)&_fdata);
 #endif
 
diff --git a/cpu/mips_pic32_common/reset_mod.S b/cpu/mips_pic32_common/reset_mod.S
index 078c2c52de4788ea5e61e56ed1a75d1f3e7d519a..78b11c496f9e0e981ba1839831c7aa11dd3ee53b 100644
--- a/cpu/mips_pic32_common/reset_mod.S
+++ b/cpu/mips_pic32_common/reset_mod.S
@@ -34,7 +34,7 @@
 	(from the 2016.05-03 version) with a couple of modifications:
 
 	#define SKIP_COPY_TO_RAM - prevents the bootloader copying the whole contents
-	of flash to ram (as we want to XIP from flash), we copy initialised data from
+	of flash to ram (as we want to XIP from flash), we copy initialized data from
 	flash to ram in 'software_init_hook'.
 
 	move .org's to before the labels to make the vector labels appear at the vector
diff --git a/dist/tools/goodfet/goodfet.bsl b/dist/tools/goodfet/goodfet.bsl
index 8947963322b1cd8678165652887b28bbc7cf6a02..6ae64cb067068c99e4fc2f81177665f6ef6a722a 100755
--- a/dist/tools/goodfet/goodfet.bsl
+++ b/dist/tools/goodfet/goodfet.bsl
@@ -296,7 +296,7 @@ class LowLevel:
 
     def comInit(self, port):
         """Tries to open the serial port given and
-        initialises the port and variables.
+        initializes the port and variables.
         The timeout and the number of allowed errors is multiplied by
         'aProlongFactor' after transmission of a command to give
         plenty of time to the micro controller to finish the command.
diff --git a/drivers/at86rf2xx/at86rf2xx_netdev.c b/drivers/at86rf2xx/at86rf2xx_netdev.c
index 445a31cf1a9fc902f85201a8cbead58c4fb22276..886f22168c25494725daa942bdd968e0c1477953 100644
--- a/drivers/at86rf2xx/at86rf2xx_netdev.c
+++ b/drivers/at86rf2xx/at86rf2xx_netdev.c
@@ -69,7 +69,7 @@ static int _init(netdev_t *netdev)
 {
     at86rf2xx_t *dev = (at86rf2xx_t *)netdev;
 
-    /* initialise GPIOs */
+    /* initialize GPIOs */
     spi_init_cs(dev->params.spi, dev->params.cs_pin);
     gpio_init(dev->params.sleep_pin, GPIO_OUT);
     gpio_clear(dev->params.sleep_pin);
diff --git a/drivers/kw2xrf/kw2xrf_netdev.c b/drivers/kw2xrf/kw2xrf_netdev.c
index ab5ce07460b93394ff458fe35bfaca7ddd379f4c..5511b5ea22725eabd94da05b0f17a5ce273574e3 100644
--- a/drivers/kw2xrf/kw2xrf_netdev.c
+++ b/drivers/kw2xrf/kw2xrf_netdev.c
@@ -56,7 +56,7 @@ static int _init(netdev_t *netdev)
 {
     kw2xrf_t *dev = (kw2xrf_t *)netdev;
 
-    /* initialise SPI and GPIOs */
+    /* initialize SPI and GPIOs */
     if (kw2xrf_init(dev, &_irq_handler)) {
         LOG_ERROR("[kw2xrf] unable to initialize device\n");
         return -1;
diff --git a/drivers/mrf24j40/mrf24j40_netdev.c b/drivers/mrf24j40/mrf24j40_netdev.c
index a39f86ae74a3a38b24e54da621921d5e74f85a0b..a910599e27b2ebbf5f11ca4a831ae17e486af4a6 100644
--- a/drivers/mrf24j40/mrf24j40_netdev.c
+++ b/drivers/mrf24j40/mrf24j40_netdev.c
@@ -69,7 +69,7 @@ static int _init(netdev_t *netdev)
 {
     mrf24j40_t *dev = (mrf24j40_t *)netdev;
 
-    /* initialise GPIOs */
+    /* initialize GPIOs */
     spi_init_cs(dev->params.spi, dev->params.cs_pin);
     gpio_init(dev->params.reset_pin, GPIO_OUT);
     gpio_set(dev->params.reset_pin);
diff --git a/sys/posix/pthread/include/pthread_cond.h b/sys/posix/pthread/include/pthread_cond.h
index 0fb70dbee01d0ae7c280921feda3f1364092eba2..a0cfc444afbf58cd83973872657e80d034573802 100644
--- a/sys/posix/pthread/include/pthread_cond.h
+++ b/sys/posix/pthread/include/pthread_cond.h
@@ -70,7 +70,7 @@ int pthread_cond_condattr_init(pthread_condattr_t *attr);
 int pthread_cond_condattr_destroy(pthread_condattr_t *attr);
 
 /**
- * @brief Get the process-shared attribute in an initialised attributes object referenced by attr
+ * @brief Get the process-shared attribute in an initialized attributes object referenced by attr
  * @note NOT USED since RIOT is a single process OS
  * @param[in] attr pre-allocated condition attribute variable structure.
  * @param[out] pshared the pre-allocated process-shared variable.
@@ -79,7 +79,7 @@ int pthread_cond_condattr_destroy(pthread_condattr_t *attr);
 int pthread_condattr_getpshared(const pthread_condattr_t *attr, int *pshared);
 
 /**
- * @brief Set the process-shared attribute in an initialised attributes object referenced by attr
+ * @brief Set the process-shared attribute in an initialized attributes object referenced by attr
  * @note NOT USED since RIOT is a single process OS
  * @param[in, out] attr pre-allocated condition attribute variable structure.
  * @param[in] pshared pshared the pre-allocated process-shared variable.