taru-adjective, adverb taking the 'to' particle
Describes something that wells up or flows continuously without stopping, often used for water, emotions, or interest. Most commonly seen in the phrase 興味津津 (with keen interest).
See also: 興味津々
彼は興味津津とその話を聞いていた。
He listened to the story with keen interest.
泉から水が津津と湧き出ている。
Water is gushing out from the spring.
A common fixed phrase meaning 'with great interest'; 津津 itself is rarely used outside this compound.
Reduplication of 津 (しん), an old word for 'water's edge' or 'ferry', extended to mean 'flowing' or 'gushing'. The exact historical derivation is uncertain.