Technically, experts consider 10 times a year or less to be a "sexless" marriage, so I'd say he's entitled to use that word.
But @Pintofcrisps, this doesn't always mean the death of the relationship. I've dealt with it myself, and now we've never been happier. If you both love each other and are committed, but sex has just fallen by the wayside or out of her priorities, then you should be able to work through this. It could possibly even be fairly easy.
For one thing, have you had a serious conversation about this issue with her (without blame or accusation), to let her know how this makes you feel, how it alienates you and damages your confidence, how it affects every aspect of your life? How it hurts you? Because research has shown that, to our brains, the pain of rejection is essentially the same as physical pain. Rejection literally HURTS.
Also, how does she react when you do have sex? Is she into it, does she enjoy it, does she say "oh that was wonderful, why don't we do this more often" after? Or does she seem distant and listless, to be giving in and letting you get on with it simply to shut you up? If it's the latter, then it may very well be over for you two for many reasons, but if it's the former, then I think you've got a cracking chance.
She honestly may not have any idea how severely this affects you - and it affects you very severely indeed, probably more than you realise - or even how important sex is in general. Sex is unbelievably important to a healthy, close, fulfilling relationship, and being desperate for sex (and for the closeness, the affirmation, the strength that comes along with it) while being constantly rejected has utterly devastating effects on the relationship and on the partner who is being rejected - often while the other partner is totally unaware of the abject misery of rejection or even of the importance of sex.
If everything else about the relationship is lovely, and you are serious about salvaging rather than ending it, there are fantastic resources available. This woman in particular, Michele Wiener-Davis, has done quite a bit of work in the field of sexless marriage. She focuses on fixing the issues, making sex a higher priority, understanding the differences in sex drive, emphasising the importance of sex to a marriage, and trying to prevent divorce. She's really wonderful.
Give this video a watch:
(Warning: this video may well make you cry, so it's probably best to watch it on your own!)
She's also got several books, but The Sex-Starved Marriage is particularly relevant.
Here are a few articles by or about her work on sexless marriages:
www.divorcebusting.com/blog/divorce-busting-101-the-sex-starved-marriage/
psychotherapynetworker.org/magazine/article/993/the-sex-starved-marriage
www.psychologytoday.com/blog/divorce-busting/201405/the-sex-starved-marriage-secret
healthresearchfunding.org/sexless-marriage-statistics/
firstthings.org/1830-2/
Sorry for the massive post, but I do hope this helps you - and anybody else going through this. I really do. It's a horrible, devastating, utterly soul-crushing thing to live with, and you simply cannot go on like this. Please read up on this subject, and then try talking to her about it. Just doing that, all by itself, honestly saved my marriage, without any outside involvement at all. I hope it can save your relationship too.
I wish you the best of luck OP. 