(chemistry)molar (one mole of substance per litre of solute)
1977, K.B. Becker, “The Synthesis of Strained Methylene‐bridged Bicyclic Olefins by the Intramolecular Wittig Reaction”, in Helvetica Chimica Acta (in English), Volume 60, Part 1, page 91:
8.5 ml (17 mmol) of a ca. 2ᴍ solution of diborane in tetrahydrofuran were added dropwise at 0° to 6.04 g (33.1 mmol) of 30 in dry tetrahydrofuran (30 ml).
2014, G.R. Palin, Chemistry for Technologists (in English), page 10:
A molar solution is one which contains one mole in every litre of solution, and so: a 5 ᴍ solution contains 5 moles per litre