From or evoking the 71st through 80th years of a century (chiefly the 1970s).

The start of the eighteenth hour of the day on the 24-hour clock i.e. 17:00. / The number one thousand seven hundred. / The year 1700.

Seven times as much; multiplied by seven. / Having seven parts; composed of seven items.

By a factor of seven.

In the seventh place; seventh in a row.

(archaic) One hundred and forty.

plural of seventeen

(US, education) The period in school that comes after sixth grade and before eighth grade.

plural of seventeenth

A Protestant Christian denomination that observes Saturday as the Sabbath