12-letter words containing l, a, m, r
- zebra mussel — a small striped freshwater mussel from NE Europe, Dreissena polymorpha: introduced to the Great Lakes in the 1980s and deleteriously affecting water pipes, other fauna, etc.
- zorn's lemma — a theorem of set theory that if every totally ordered subset of a nonempty partially ordered set has an upper bound, then there is an element in the set such that the set contains no element greater than the specified given element.