A Hitch

1. A sudden pull.
2. Any of various knots used to attach a rope to an object other than another rope.[1]
3. A fastener or connection point, as for a trailer.
4. (informal) A problem, delay or source of difficulty.
5. A hidden or unfavorable condition or element.

Synonym: catch

6. (military, slang) A period of time spent in the military