peep

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To utter short, soft, high-pitched sounds, like those of a baby bird; cheep.
• intransitive verb To speak in a hesitant, thin, high-pitched voice.
• noun A short, soft, high-pitched sound or utterance, like that of a baby bird.
• noun A slight sound or utterance.
• noun Any of various small North American sandpipers.
• intransitive verb To peek furtively; steal a quick glance.
• intransitive verb To peer through a small aperture or from behind something.
• intransitive verb To appear as though emerging from a hiding place.
• intransitive verb To cause to emerge or become partly visible.
• noun A quick or furtive look or glance.
• noun A first glimpse or appearance.

from The Century Dictionary.

• noun The cry of a young chick or other little bird.
• noun A sandpiper; a sandpeep.
• To have the appearance of looking out or issuing from a narrow aperture or from a state of concealment; come partially into view; begin to appear.
• To look (out or in) pryingly, slyly, or furtively, as through a crevice or small aperture; look narrowly, slyly, or pryingly; take a sly or furtive look; peer; peek.
• To let appear; show.
• noun A sly or furtive look through or as if through a crevice; a hurried or partial view; a glimpse; hence, the first looking out of light from the eastern horizon.
• noun A crevice or aperture; a slit or opening affording only a narrow or limited view.
• noun Specifically The slit in the leaf of a rifle-sight.
• noun A pip.
• To chirp, cheep, or pipe; utter a shrill thin sound, as a young chick.
• To speak in a piping or chirping tone.
• To speak.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To cry, as a chicken hatching or newly hatched; to chirp; to cheep.
• intransitive verb To begin to appear; to look forth from concealment; to make the first appearance.
• intransitive verb To look cautiously or slyly; to peer, as through a crevice; to pry.
• intransitive verb an adjustable piece, pierced with a small hole to peep through in aiming, attached to a rifle or other firearm near the breech.
• noun The cry of a young chicken; a chirp.
• noun First outlook or appearance.
• noun A sly look; a look as through a crevice, or from a place of concealment.
• noun Any small sandpiper, as the least sandpiper (Trigna minutilla).
• noun The European meadow pipit (Anthus pratensis).
• noun a small show, or object exhibited, which is viewed through an orifice or a magnifying glass.
• noun [Cant] the Irish insurgents of 1784; -- so called from their visiting the house of the loyal Irish at day break in search of arms.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb To look, especially while trying not to be seen or noticed.
• noun A quick look or glimpse, especially a furtive one.
• noun obsolete A spot on a die or domino.
• noun A quiet sound, particularly one from a baby bird.
• noun A feeble utterance or complaint.
• noun The sound of a steam engine's whistle; typically shrill.
• noun A kind of bird; a sandpiper.
• verb To make a soft, shrill noise like a baby bird.
• verb To speak briefly with a quiet voice.
• noun UK, slang person.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb make high-pitched sounds
• verb cause to appear
• noun the short weak cry of a young bird
• verb appear as though from hiding
• verb look furtively