septuple

1. (transitive) To multiply by seven.Examples: "[…] hee is rid of the Deuill. Now he that is quit of so bad a Guest, shall septuple his owne woes by his re-entertainment."; "The intensity of solar radiation is nearly seven times greater on Mercury than on the earth, and on Uranus 330 times less; the proportion between the two extremes being that of upwards of 2000 to one. Let any one figure to himself the condition of our globe, were the sun to be septupled, to say nothing of the greater ratio!"transitive

2. (intransitive) To increase by a factor of seven.Examples: "[…] Levi Strauss had caught a wave. Between 1962 and 1970, its sales and net profits grew fivefold and between 1970 and 1977 its sales again quintupled while profits almost septupled."intransitive