To engage the attention of; to awaken interest in; to excite emotion or passion in, in behalf of a person or thing.

“Action films don't really interest me.”

To be concerned with or engaged in; to affect; to concern; to excite.

To cause or permit to share.

Having or showing interest.

“I'm very interested in going to see that play.”

Motivated by considerations of self-interest; self-serving.

Owning a share of a company.