21-letter words containing a, l, o, g, i, c
- supergranulation cell — one of a number of large convection cells in the photosphere and chromosphere of the sun, each having a diameter of 10,000–20,000 miles (16,000–32,000 km) and lasting longer than a day.
- teleological argument — the argument purporting to prove the existence of God from empirical facts, the premise being that the universe shows evidence of order and hence design
- the rock of gibraltar — a limestone promontory at the tip of S Spain
- threshold wage policy — a policy whereby wages are increased in accordance with inflation
- to kill a mockingbird — a novel (1960) by Harper Lee.
- topological invariant — a property of a topological space that is a property of every space related to the given space by a homeomorphism.