ETYMOLOGY
from gain- (against, in opposition to) + strive (to endeavour vigorously)
EXAMPLE (for vb. 1.)
“… Giue vs that peace, which we doo lacke,
Through misbelief and ill lyfe:
Thy Word to offer thou dost not slacke,
Which we unkindly gainstriue.
With fire and swoord,
This healthfull woord:
Some persecute and oppres:
Some with the mouth,
Confess the truth,
Wythout sincere godlynes. …”
From: The Whole book of Psalms: collected into English metre, by Thomas Sternhold, John Hopkins, and others, 1569
“Da Pacem, Domine“
Lexicophilia 