The Collaborative International Dictionary
Overlash
Overlash \O`ver*lash"\, v. i. [Cf. Prov. E. lash extravagant,
lashing lavish.]
To drive on rashly; to go to excess; hence, to exaggerate; to
boast. [Obs.]
--Barrow.
Wiktionary
overlash
vb. 1 (context obsolete English) To drive on rashly; to go to excess. 2 (context obsolete by extension English) To exaggerate; to boast.