noun
tombolo
A geological term for a sandbar or spit connecting an island to the mainland or another island. Also referred to as トンボロ.
See also: トンボロ
陸繋砂州は、島と本土をつなぐ砂の堆積地形です。
A tombolo is a sand deposition landform that connects an island to the mainland.
Synonymous loanword from Italian; トンボロ is more common in casual or non-specialist contexts, while 陸繋砂州 is the formal Japanese geological term.
Compound of 陸 (land), 繋 (connect), and 砂州 (sandbar). The reading りくけいさす follows standard on'yomi for the kanji.