An example of something tinny is pewter.
An example of a tinny sound is the high pitched sound of an out of tune string instrument.
An example of a tinny taste is the taste of canned tuna.
An example of a tinny material is aluminum foil.
Tinny canned food.
A high tinny voice.
The object had a tinny appearance.
The shop was filled with tinny tourist geegaws.
The piano was not simply out of tune, but had become downright tinny.