Definitions for undeviating
Random House Webster's College Dictionary
going directly ahead from one point to another without veering or turning aside
"some people see evolution as an undeviating upward march from simple organisms to the very complex"; "a straight and narrow tree-lined road unswerving across the lowlands"
used of values and principles; not subject to change; steady
that does not deviate, veer or turn aside; unswerving
that does not change; steady