increased by; with the addition of

Four plus five equals nine

We have to repay the debt plus interest

and also

The job needs experience plus patience

an added quantity

a positive factor, quantity, or quality

a surplus

= plus sign

arithmetically or electrically positive

additional and welcome

a plus factor

A plus factor is its nearness to the shops

said esp of an academic grade: slightly higher than that specified

He got a B plus

He got a B plus for his essay