at a guess

Prepositional phrase

informal

(informal) Upon cursory examination; at a glance.

Japanese Meaning

ざっと眺めたところ / ひと見での印象として

At a guess, there were about fifty people in the room when I arrived.

ざっと見たところ、私が到着したとき部屋には約50人いました。

Sense（1）

(informal) Upon cursory examination; at a glance.

The woman opposite him was a mere girl - twenty at a guess.