(endeavours, endeavouring, endeavoured)
Note: in AM, use 'endeavor'
1.
If you endeavour to do something, you try very hard to do it. (FORMAL)
I will endeavour to arrange it...
= strive
VERB: V to-inf
2.
An endeavour is an attempt to do something, especially something new or original. (FORMAL)
His first endeavours in the field were wedding films.
N-VAR: usu with supp, oft N to-inf