I know late wife is a common term (dead wife). How about late girlfriend? If that's not the case, what's the most used term?
Depends on the circumstances; "dead girlfriend" definitely sounds more dramatic and gives a sense of someone who may have been killed or died in an accident. It's a very direct expression and some might feel uncomfortable using it. If you have been following the Pistorius murder trial the term is frequently used
Oscar Pistorius breaks down describing shooting dead girlfriend Reeva Steenkamp source
The athlete, the first double-amputee to ever compete in an Olympics, told his dead girlfriend’s family he was sorry — a move that immediately struck some lawyers as odd. source
On the other hand "late girlfriend" is a softer term, and suggests that the speaker remembers his girlfriend affectionately and with fondness.
I saw the video for P.S. I LOVE U. I remembered my late girlfriend and cried… source
Both expressions are commonly used.
Google Ngram charts
The OP's question led me to investigate further, so I turned to Google Ngram to see what I could find. Generally speaking, I'm not a fan of this tool as I've seen too many people abuse this feature in the past, but in this case the results are curious and they might be of interest. I'm posting the American English corpus charts because the British English corpus, astonishingly, had no results for "his late girlfriend". The graphs are set between 1950 to 2000. We are concerned with the modern usage of "late girlfriend" not in its history.
The graph above appears to show an impressive divergence, I then added the following expressions; his late wife and his dead wife, in order to compare the results.
Now the divergence between late vs dead girlfriend appears to be practically insignificant. It's worth mentioning that the term "late + spouse/relative" always comes second to "dead + spouse/relative". Here's another graph but without the term wife
I leave the OP to draw his own conclusions.
It would be OK if she died while still being your girlfriend.
If she is still alive and you have split up it's much more common to say
Slightly humorous warning below (that should appear if you mouse over it)
A degree of caution is required should you have split up and then your ex-girlfriend died. This would make her your late ex-girlfriend which could be misunderstood for something quite different.
Yes; this usage of the word late has no specific restriction to wives, girlfriends, or any other particular relationship or position of people. It is simply a somewhat respectful, tactful way to talk about any dead person. It is mostly used for people who have died comparatively recently, but not exclusively; the subtleties of that point are discussed in some excellent answers here.
Using the adjectives deceased or departed would prevent the unintentional ambiguity with the alternate meanings for dead such as boring, cadaverous, cold, etc. The adjective late has even more ambiguity even if it feels kinder. But the phrase "dead girlfriend" feels almost disrespectful to her in my intuitions as a listener.
Ok. As I have a girlfriend that died recently (not joking. It was diabetes). I struggled with this term. Now saying my departed girlfriend really dose sound old fashioned. Saying dead girlfriend made people fell bad as it sounds as if they have just died also I personally think it sounds harsh and uncaring (but that's me). deceased girlfriend is ok as it indicates that your girlfriend has died but dose not give the impression it has happoned recently. If used in the right context late is fine for example my late girlfriend liked roses. (Honestly you would have to be stupid to think that his girlfriend who is always later for him to refer to her as his late girlfriend liked roses). I finally settled on a combination of late or deceased depending on who I'm talking to and the subject of the conversation. If I'm talking about her in a fond past tense I use late girlfriend. If answering a question like for example if someone says (so do you have a girlfriend) saying she's late well you get the picture. That's when I say she's deceased
It's not a commonly used term that I'm aware of, and I'm sure that you next girlfriend won't appreciate your use of that term, should you choose to continue dating despite your epic heartbreak.
Former girlfriend or one of your
old girlfriends sounds a lot more like you parted on mutual terms, if you want to avoid the negative connotations of ex-girlfriend. If anyone inquires as to what happened, you can then explain if you want to.