The state of being certain.
A fact or truth unquestionably established.
An instance of being certain.
To strive, to labour in difficulty, to fight (for or against), to contend.
To strive, or to make efforts, with a twisting, or with contortions of the body.
A contortion of the body in an attempt to escape or to perform a difficult task.
Strife, contention, great effort.