Masculin or feminin???????? Le genre des mots

[May]

Comment savoir si ce mot est masculin ou feminin?
How to know the gender of the word, masculin or feminin?
Masculin
 words with these endings are masculin with some exceptions...
-age, -an, -c, -d, -eme, -g, -i, -in, -is, -iste, -k, -l, -lon, -m, -non, -o, -ome, -r, -sme, -t, -taire, -ton, -tre, -u, -us.

Endings          Exceptions 
-age         cage plage image nage page rage
-an          médian maman
-c           fac       
-i           merci fourmi foi loi
-in          main fin
-is          brebis fois souris oasis
-iste        modiste liste piste  
-m           faim     
-o           météo dactylo dynamo steno magnéto moto    
-r           mer chair minceur douceur froideur grandeur
             profondeur odeur largeur valeur fleur couleur
             soeur peur vapeur erreur horreur cour tour

-t           forêt nuit dent part plupart    
-tre         fenêtre huître vitre rencontre montre lettre
-u           eau peau vertu
      

Féminin
 words with these endings are feminin with some exceptions...

-ade, -aison, -ce, -ee, -ie, -iere, -ine, -ion, -ite, -lle, -se, -tte,-ude,-ure.

ending        Exceptions 
-ade         jade grade stade
-ce          espace crustace exercice bénéfice office artifice
             précipice dentifrice armistice vice service silence
             prince commerce pouce
-ee          lycée périgée trophée pedigree musée
-ie          incendie cryptographie périhélie génie foie
             parapluie
-iere        arrière derrière cimetière
-ine         domaine capitaine ciné pipeline moine patrimoine
             magazine
-ion         ion million billion camion dominion lampion
             scorpion espion démilitarisation antivivisection
             bastion attribution avion
-ite         trilobite anthracite plébiscite gîte graphite
             satellite théodolite comité ermite termite
             granite rite mérite site opposite
-lle         intervalle vermicelle scelle braille mille
             gorille vaudeville
-se          vase malaise suspense sconse opposé exposé gypse
             inverse colosse carrosse pamplemousse
-tte         squelette
-ude         prélude interlude coude
-ure         dinosaure centaure kilowattheure sulfure/nitrure/...
             parjure murmure 

[Neil Coffey]

There's some material I put together a while ago on telling the gender of French nouns from their ending etc.

Note that gender isn't just determined by noun ending: some semantic and grammatical elements also come into play.

Incidentally, re the list above, termite is interesting because there actually isn't much consensus about its gender. For what it's worth, Larousse list it as masculine. Wikipedia rather dogmatically has a statement saying: "Le mot "termite" est masculin. Contrairement aux idées reçues, on dit bien 'un termite' et non 'une termite'", although as far as I can observe, actual usage really isn't as clear-cut as either of these sources make out (and if it was, they wouldn't need to bother mentioning it of course).

It's also worth pointing out that the exceptions don't tend to occur when suffixes like -ie are genuinely used as suffixes-- or in other words, when you have related pairs ending in -ique (adjective) vs -ie (noun), it's practically impossible for the noun not to follow the expected gender.

Incidentally (but it's really not an important point), I think the word opposite (which is essentially obsolete, though you'll occasionally find in literature) is probably more appropriately described as being an adjective. But as a whole, it's used in phrases like à l'opposite de... rather than on its own like a "normal" adjective.