shrink

A negative term for a very shy person. After years of being seen as nothing more than a shrinking violet, Christine decided to overcome her fears and start talking to strangers.

Fig. someone who is very shy and not assertive. I am not exactly a shrinking violet, but I don't have the guts to say what you said to her.

a very shy person (usually negative) She's no shrinking violet. I wouldn't exactly describe him as a shrinking violet.

An extremely shy person, as in She was a shrinking violet until she went away to college. This metaphoric idiom refers to the flower, but the precise allusion is unclear, since violets thrive under a variety of conditions and often are considered a garden weed. [Early 1900s]

A shy person. The violet flower gives the impression of shyness, growing as it does close to the protective ground and often beneath other plants, shrubs and trees. Compared to other larger foliage, violets do seem to look as though they are shrinking, growing smaller. As applied to shy people, the phrase first appeared in both America and Great Britain in the 1820s.