Involute

involute \ˈin-və-ˌlüt\ adjective: 1 a. curled spirally, b. curled or curved inward, c. having the edges rolled over the upper surface toward the midrib {an involute leaf}, d. having the form of an involute {a gear with involute teeth},
2: involved, intricate

involute \ˈin-və-ˌlüt\ noun: a curve traced by a point on a thread kept taut as it is unwound from another curve {involute of a circle}

involute \ˌin-və-ˈlüt\ intransitive verb: 1. to become involute, 
2 a. to return to a former condition, b. to become cleared up; disappear

Etymology: Latin involutus concealed, from past participle of involvere

Note that the stress is placed on the first syllable when involute is used as an adjective or noun, and on the last syllable when it’s a verb.