Choose the correct one-word substitute for: 'A deep and seemingly bottomless chasm'.

Correct — C. The trigger is seemingly bottomless. Abyss comes through Latin from the Greek abussos, bottomless: a- (without) plus bussos (depth).

The word's own root is the definition, so abyss is the deep, seemingly bottomless chasm.

Crevasse, crater and gorge are real hollows, but none carries the idea of having no bottom → option (c).

Why the others are wrong

• (a)
  Crevasse — Crevasse is a deep open crack, especially in a glacier. It is the closest trap because it is deep, but it is defined by ice, not by bottomlessness.
• (b)
  Crater — Crater is a bowl-shaped hollow, made by an impact or at the mouth of a volcano. A bowl has a visible floor, the reverse of bottomless.
• (d)
  Gorge — Gorge is a narrow valley between hills with steep rocky walls, usually with a stream running through it. It has a floor, so it is not bottomless.

All four options are landforms with depth, so the one unusual word in the definition has to decide: bottomless.

A crevasse is a crack in ice, a crater is a bowl, a gorge is a river valley, and each has a floor. Abyss alone is defined by the absence of one.

Abyss is also used figuratively for a catastrophe or a deep state of despair: the abyss of war.

Key facts

• Abyss comes from the Greek abussos, bottomless.
• A crevasse is a deep open crack, especially in a glacier.
• A gorge is a narrow, steep-sided valley, usually with a stream running through it.
• Abysmal, from the same source, means extremely bad.

Common traps

• Choosing crevasse because it is deep and narrow, without testing it against 'bottomless'.
• Mixing up crevasse and crevice, which differ in size and in what they split.

No directly related past PYQ was found.