(obsolete) The hentaigana syllable that is used to represent tsu or to in old Japanese text.

To improve (in reference to a society's technological capability or general quality of life). / To advance in proficiency; to make progress in the development of a skill.

chugging; downing

(Buddhism, rare) word added to the end of a mantra, used as an intention for blessing, good luck, etc., or as an oblation