15-letter words containing a, i, d, s, t, o
- thorndike's law — the principle that all learnt behaviour is regulated by rewards and punishments, proposed by Edward Lee Thorndike (1874–1949), US psychologist
- thousand island — of or relating to the Thousand Islands or their inhabitants
- tie one's hands — the terminal, prehensile part of the upper limb in humans and other primates, consisting of the wrist, metacarpal area, fingers, and thumb.
- tirso de molina — Luis [loo-ees] /luˈis/ (Show IPA), 1535–1600, Spanish Jesuit theologian.
- titius-bode law — Bode's law.
- to make friends — If you make friends with someone, you begin a friendship with them. You can also say that two people make friends.
- tokelau islands — a group of islands in the S Pacific Ocean belonging to New Zealand. 4 sq. mi. (10 sq. km).
- trading profits — profits made from the buying and selling of goods and services
- trans-jordanian — of or relating to the former Trans-Jordan (now Jordan) or its inhabitants
- transfer window — the period during the year in which a football club can transfer players from other teams into their own
- trapdoor spider — any of various, often large, spiders (esp. family Ctenizidae) that dig a burrow and cover the entrance with a hinged lid like a trapdoor
- trojan asteroid — one of a number of asteroids that have the same mean motion and orbit as Jupiter, preceding or following the planet by a longitude of 60°
- two-dimensional — having the dimensions of height and width only: a two-dimensional surface.
- ultra-modernist — very advanced in ideas, design, or techniques.
- ultrafastidious — extremely fastidious
- unconsolidation — an act or instance of consolidating; the state of being consolidated; unification: consolidation of companies.
- unconstrainedly — in an unconfined manner
- undemonstrative — not given to open exhibition or expression of emotion, especially of affection.
- underestimation — to estimate at too low a value, rate, or the like.
- undisappointing — not disappointing
- unsophisticated — not sophisticated; simple; artless.
- victoria island — an island off the coast of N Canada, in the Arctic Ocean. 80,340 sq. mi. (208,081 sq. km).
- winter holidays — a period of rest from work or studies taken in winter