Turritis glabra (syn. Arabis glabra), a tall, slim, grey-green plant with small creamy flowers at the top of the stem.

Sisymbrium officinale, a brassicaceous plant with edible leaves and seeds.

plural of French mustard

plural of treacle mustard

(idiomatic) To suffice; to be good or effective enough.

(simile) Very keen, enthusiastic, eager.

(technical) Mustard gas.

The hot pungent oil expressed from mustard seeds; used sparingly as a food dressing. / (organic chemistry) The essential oil allyl isothiocyanate, also obtained from mustard seeds.

A vesicant gas, bis (2-chloroethyl) sulfide, (ClC₂H₄)₂S, once used in chemical warfare.

(chemistry) Any of a series of compounds, analogous to mustard gas with sulfur replaced by nitrogen, that have been used in the treatment of cancer.