Outer part of a strawberry

• Part of a sunflower
• Fruit of the buttercup
• Part of a strawberry
• Small dry indehiscent fruit with the seed distinct from the fruit wall
• One-seeded fruit, botanically
• Berry nub
• Fruit of a buttercup

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Achene \A*chene"\, Achenium \A*che"ni*um\n. [Gr. 'a priv. + ? to gape.] (Bot.) A small, dry, indehiscent fruit, containing a single seed, as in the buttercup; -- called a naked seed by the earlier botanists. [Written also akene and ach[ae]nium .]

Wikipedia Word definitions in Wikipedia
An achene (Greek ἀ, a , privative + χαίνειν, chainein , to gape; also sometimes referred to as akene and occasionally achenium or achenocarp ) is a type of simple dry fruit produced by many species of flowering plants . Achenes are monocarpellate (formed ...