Emily Dickinson Lexicon

THIN, v.t. [Sax. thinnian; Russ. tonyu; L. tenuo. See Attenuate.]

1. To make thin; to make rare or less thick; to attenuate; as, to thin the blood.
2. To make less close, crowded or numerous; as, to thin the ranks of an enemy; to thin the trees or shrubs of a thicket.
3. To attenuate; to rarefy; to make less dense; as, to thin the air; to thin the vapors. Thin out, in geology: when strata diminish in thickness until they disappear, they are said to thin out.