Tera (寺) means "temple" in Japanese. Her name may be derived from terasen (寺銭), literally "temple money", a fee charged by a gambling house. This follows the gambling-themed names of Zoro's relatives.
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↑ 1.01.11.21.3SBSOne Piece Manga — Vol. 105 (p. 132), Tera is included in Zoro's family tree.