‏ممارسة، مباشرة، مهنة، مطاردة، ملاحقة، حرفة، عمل، نشاط، متابعة، مواصلة‏

the act of pursuing in an effort to overtake or capture: tracking, shadowing, move, tailing, stalking, motion, stalk, pursual, following, chase, trailing, movement
a search for an alternative that meets cognitive criteria: wild-goose chase, search, quest, pursuance
a diversion that occupies one's time and thoughts (usually pleasantly): recreation, sideline, spare-time activity, by-line, avocation, diversion, pastime, interest, hobby
an auxiliary activity: sideline, speleology, spare-time activity, by-line, avocation, pastime, interest, hobby, spelaeology