1.A little king; a weak or insignificant king.
2.(Zool.) Any one of several species of small singing birds of the genus Regulus and family Sylviidae. Note: The golden-crowned kinglet (Regulus satrapa), and the rubycrowned kinglet (Regulus calendula), are the most common American species. The common English kinglet (Regulus cristatus) is also called golden-crested wren, moonie, and marigold finch. The kinglets are often popularly called wrens, both in America and England.