the word 'teary' is a transparent english formation, directly combining the old english noun for the liquid secreted by the eye, 'tēar', with the common germanic adjectival suffix '-ig', which evolved into modern english '-y'. the root 'tēar' itself descends from proto-germanic 'tahrą' and can be traced further back to the proto-indo-european root 'dakru-', which also gave rise to the greek 'dákry' and latin 'lacrima' via a different phonetic branch. the logic of the word is straightforward: the suffix '-y' attaches to the noun to create an adjective meaning 'characterized by or full of tears,' perfectly capturing its modern senses of either being in a state of weeping or inducing such a state.

Structure: tear (a drop of liquid from the eye) + y (adjective-forming suffix) tear (from old english 'tēar', of germanic origin; related to old norse 'tár', greek 'dakry') + y (from old english '-ig', an adjective-forming suffix)