irregular from Latin formica ant — more at pismire
First Known Use: 1790
Medical Definition of FORMIC ACID
: a colorless pungent fuming vesicant liquid acid CH2O2 found especially in ants and in many plants and used chiefly in dyeing and finishing textiles
Simplest carboxylic acid, chemical formula HCOOH. It is secreted by some insects, especially red ants (its name comes from the Latin word for ant), in their bite or sting. It has many industrial uses, in textile and leather manufacture, as an industrial solvent, and as an intermediate.