1) a deep, long channel dug in or between fields, at the sides of a road etc, used to hold or carry off water (ditch)
2) serious; very sad and disappointing; (a place with) a hole dug in the ground for a dead body (grave)
3) a deep ditch dug in the ground, e.g. for the draining of water (trench)
that cannot be moved; not able, refusing to be affected or changed
fixed, stubborn