Adjective

(er)

Refusing to move or to change one's opinion; obstinate; firmly resisting.

He is pretty stubborn about his political beliefs, so why bother arguing?

Blood can make a very stubborn stain on fabrics if not washed properly.

Adjective

(en adjective)

Characterized by exceptionally early development or maturity.

* {{quote-news, year=2014

, date=November 14 , author=Stephen Halliday , title=Scotland 1-0 Republic of Ireland: Maloney the hero , work=The Scotsman citation , page= , passage=Scotland’s most encouraging early source of an attacking threat was Andrew Robertson as the precocious left-back charged forward to good effect on a couple of occasions. }}

*

Both groups, also, have already evolved precocious (intracapsular) spore germination.

Exhibiting advanced skills at an abnormally early age.

The precocious child began reading the newspaper at age four.