Lewis & Short

frĭgūtĭo (frĭguttio, fringūtio, frĭgultio, fringultio, fringulo), īre, v. n. and a. [a lengthened form of 2. frigo], to twitter, chirp.

  1. I. Lit., of birds: merulae in remotis tesquis frigutiunt, App. Flor. p. 358, 22: fringulit et graculus, Poët. ap. Anthol. Lat, 5, 43, 124.
  2. II. Transf., of a person who speaks indistinctly, to stammer, stutter.
    1. A. Neutr. (ante- and post-class.): murmurare potius et friguttire quam clangere, Front. de Eloqu. p. 229 ed. Mai.; cf.: saepe in rebus nequaquam difficilibus fringultiat vel omnino obmutescat, App. Mag. p. 296, 21: haec anus admodum frigultit, Enn. ap. Fulg. 562, 24: quid friguttis? Plaut. Cas. 2, 3, 49 (also ap. Varr. L. L. 7, § 104).
    2. B. Act., to stammer forth: vix singulas syllabas fringutiens, App. Mag. p. 336, 18.