behind
noun
the fleshy part of the human body that you sit on
“he deserves a good kick in the butt”
“are you going to sit on your fanny and do nothing?”
adjective
having the lower score or lagging position in a contest
“behind by two points”
“the 8th inning found the home team trailing”
adverb
in or to or toward the rear
“he followed behind”
“seen from behind, the house is more imposing than it is from the front”
remaining in a place or condition that has been left or departed from
“when he died he left much unfinished work behind”
“left a large family behind”
of timepieces
“the clock is almost an hour slow”
“my watch is running behind”
Synonymsslowin or into an inferior position
“fell behind in his studies”
“their business was lagging behind in the competition for customers”
in debt
“he fell behind with his mortgage payments”
“a month behind in the rent”
Source: WordNet 3.1, Princeton University