(n): green plant having a vascular system: ferns, gymnosperms, angiosperms
(n): a person who crawls or creeps along the ground
(n): a human being
(n): any of various small insectivorous birds of the northern hemisphere that climb up a tree trunk supporting themselves on stiff tail feathers and their feet
(n): passerine bird having specialized vocal apparatus
Also slang for a creepy person.
"Stop being such a creeper."
Also a slang term for 'urban explorer'.