librate

verb

1. (intransitive)To oscillate (like the beam of a balance).

   “Their parts all librate on too nice a beam.”

   “The currently observed orbital resonances at the 2:1 mean motion commensurabilities involving Io-Europa and Europa-Ganymede are such that the resonance variables #92;theta#95;1#61;#92;lambda#95;1-2#92;lambda#95;2#43;#92;omega#95;1 and #92;theta#95;3#61;#92;lambda#95;2-2#92;lambda#95;3#43;#92;omega#95;2 librate about 0° and #92;theta#95;2#61;#92;lambda#95;1-2#92;lambda#95;2#43;#92;omega#95;2 librates about 180°, all with small amplitude.”

2. (figuratively, intransitive)To waver or deliberate between two opposing thoughts or choices.

   “But she winds about him coil after coil of her glittering rhetoric, in which reason holds its own as it librates with specious feeling.”

3. (intransitive)To be poised; to balance oneself.

   “Her playful Sea-horse […] His watery way with waving volutes wins, / Or listening librates on unmoving fins.”

4. (obsolete, transitive)To place in a balance; to weigh.

noun

1. (historical)A piece of land having a value of one pound per year.