oblongate
To extend into an oblong form; to elongate
Fruit very small, the least of all the varieties, a little more long than broad, having a very conspicuous deeply marked suture, extending to the apex, on one side of which it oblongates into a very small acute nipple.
To give an oblong shape to (something).
Where it comes from
From New Latin oblongātus, see Etymology 1 and -ate (verb-forming suffix).
Adapted from the Wiktionary entry oblongate (CC BY-SA 4.0).