waif(n = noun.person) street child - a homeless child especially one forsaken or orphaned; "street children beg or steal in order to survive"
is a kind of child, fry, kid, minor, nestling, nipper, shaver, small fry, tiddler, tike, tyke, youngster

1.  Goods found of which the owner is not known; originally, such goods as a pursued thief threw away to prevent being apprehended, which belonged to the king unless the owner made pursuit of the felon, took him, and brought him to justice. Blackstone. [1913 Webster]

2.  Hence, anything found, or without an owner; that which comes along, as it were, by chance. Tennyson. [1913 Webster]

3.  A wanderer; a castaway; a stray; a homeless child. [1913 Webster]
"A waif
Desirous to return, and not received." [1913 Webster]

waif, n.
1 a homeless and helpless person, esp. an abandoned child.
2 an ownerless object or animal, a thing cast up by or drifting in the sea or brought by an unknown agency.

Idiom:
waifs and strays 1 homeless or neglected children.
2 odds and ends.

Derivative:
waifish adj.

Etymology:
ME f. AF waif, weif, ONF gaif, prob. of Scand. orig.

N  good, benefit, advantage, improvement, greatest good, supreme good, interest, service, behoof, behalf, weal, main chance, summum bonum, common weal, consummation devoutly to be wished, gain, boot, profit, harvest, boon, good turn, blessing, world of good, piece of good luck, piece of good fortune, nuts, prize, windfall, godsend, waif, treasure-trove, good fortune, happiness, goodness, utility, remedy, pleasure giving, commendable, useful, good, beneficial, well, aright, satisfactorily, favorably, not amis, all for the best, to one's advantage, in one's favor, in one's interest, so far so good, magnum bonum.

N  relinquishment, abandonment, desertion, defection, secession, withdrawal, cave of Adullam, nolle prosequi, discontinuance, renunciation, abrogation, resignation, desuetude, cession, unpursued, relinquished, relinquishing, Int, avast!, aufgeschoben ist nicht aufgehoben, entbehre gern was du nicht hast, relinquishment, abandonment, renunciation, expropriation, dereliction, cession, surrender, dispensation, quitclaim deed, resignation, riddance, derelict, foundling, jetsam, waif, discards, culls, rejects, garbage, refuse, rubbish, relinquished, cast off, derelict, unowned, unappropriated, unculled, left, Int, away with!.