18-letter words containing h, e, m, l, y, t
- thermal efficiency — the ratio of the work output of a heat engine to the heat input expressed in the same units of energy.
- three-body problem — the problem of calculating the motions of three bodies in space moving under the influence of only their mutual gravitational attraction.
- triarylmethane dye — any of the class of dyes containing three aryl groups attached to a central carbon atom: used chiefly for dyeing cotton, wool, and silk.
- vitamin a aldehyde — retinal2 .
- wesleyan methodist — a member of any of the churches founded on the evangelical principles of John Wesley.
- white trumpet lily — a lily, Lilium longiflorum, of Japan, having fragrant, pure white, trumpet-shaped flowers nearly 7 inches (18 cm) in length.
- witch hazel family — the plant family Hamamelidaceae, characterized by trees and shrubs having alternate, simple leaves, flowers in clusters or heads, and fruit in the form of a double-beaked woody capsule, and including the sweet gum, witch alder, and witch hazel.
- zermelo set theory — (mathematics) A set theory with the following set of axioms: Extensionality: two sets are equal if and only if they have the same elements. Union: If U is a set, so is the union of all its elements. Pair-set: If a and b are sets, so is {a, b}. Foundation: Every set contains a set disjoint from itself. Comprehension (or Restriction): If P is a formula with one free variable and X a set then {x: x is in X and P(x)}. is a set. Infinity: There exists an infinite set. Power-set: If X is a set, so is its power set. Zermelo set theory avoids Russell's paradox by excluding sets of elements with arbitrary properties - the Comprehension axiom only allows a property to be used to select elements of an existing set.