'Steepen' definitions:
Definition of 'steepen'
From: WordNet
verb
Become steeper; "The mountain side has steepened"
verb
Make steeper; "The landslides have steepened the mountain sides"
Definition of 'Steepen'
From: GCIDE
- Steepen \Steep"en\ (st[=e]p"'n), v. i. [imp. & p. p. Steepened (st[=e]p"'nd); p. pr. & vb. n. Steepening.] To become steep or steeper. [1913 Webster]
- As the way steepened . . . I could detect in the hollow of the hill some traces of the old path. --H. Miller. [1913 Webster]