S is for Streak

Photo of a group of tigers
Eustaquio Santimano / CC BY-SA

Sis forStreak (tigers)

A group of tigers is called a streak, or an ambush.
Collective nouns
Photo of streaky clounds
Luis Argerich / CC BY-SA

Sis forStreak (shape)

A streak is a long, narrow band of something. A streak might be a dirty mark, a patch of color, or even a cloud formation.
Shapes