What does “un métier ingrat” mean in French?

Applied to a person, ingrat means ungrateful. Applied to work it flips direction: un métier ingrat is a thankless job — one that gives back less than it takes, however well you do it. The effort is real and the recognition never arrives. Same adjective, and the noun it attaches to decides which way the ingratitude runs.

A third sense covers appearance: l’âge ingrat is the awkward stage of adolescence, when childhood charm has gone and adult poise has not turned up yet, and des traits ingrats means unflattering features. This farewell speech at a fire station uses the work sense — on fait un métier qui parfois peut être ingrat — and follows it with un travail où on peut nous regarder de haut, regarder quelqu’un de haut being the standard idiom for looking down on someone.