BABYSIT
sit, baby-sit, babysit
(verb) work or act as a baby-sitter; “I cannot baby-sit tonight; I have too much homework to do”
babysit, baby-sit
(verb) take watchful responsibility for; “I baby-sit the neighbor’s plants when she is out of town”
Source: WordNet® 3.1
Etymology
Verb
babysit (third-person singular simple present babysits, present participle babysitting, simple past and past participle babysat)
To watch or tend someone else's child for a period of time, often for money.
(transitive, informal) To watch or attend anything or anyone unnecessarily closely; to have to help or coax too much.
Source: Wiktionary