The Collaborative International Dictionary
Sea apple \Sea" ap"ple\ (Bot.)
The fruit of a West Indian palm ( Manicaria Plukenetii),
often found floating in the sea.
--A. Grisebach.
Wiktionary
n. 1 A round, colourful sea cucumber of the genus (taxlink Paracucumaria genus noshow=1) and (taxlink Paracolochirus genus noshow=1), found primarily in Indo-Pacific waters. 2 The fruit of a West Indian palm ((taxlink Manicaria plukenetii species noshow=1) ⇒ ) (taxlink Manicaria saccifera species noshow=1), often found floating in the sea.
Wikipedia
Sea apple is a common name for the colorful and somewhat round sea cucumbers of the genera Paracucumaria and Pseudocolochirus, found in Indo-Pacific waters. Sea apples are filter feeders with tentacles, ovate bodies, and tube-like feet. They can release their internal organs or a toxin into the water when stressed.
Usage examples of "sea apple".
A Lennox pressed is a Dead Sea apple, held by London instead of by Paris.