Single-character 斥 is literary/written; in everyday speech you'll hear the compounds: 训斥 (xùnchì) 'to reprimand,' 斥责 (chìzé) 'to rebuke,' 排斥 (páichì) 'to reject/exclude,' 斥候 (chìhòu) 'scout (military).'
history
An old graph: in oracle-bone script 斥 depicts pushing/casting away. The 'reconnoiter' and 'expand territory' senses come from military Classical Chinese — visible in the 史记 (Shǐjì) when describing border patrols and territorial expansion of the Han.
