The card does really need to say "family member **of a union/EEA citizen**" before it has any effect for the UK.  Those cards are only supposed to be issued when the union citizen lives in a _different_ member state than the one of his citizenship, which is why your card does not say that.

Even if you had one of those cards, the UK have been sort of reluctant to accept them, and the [official guidance from the UK government](https://www.gov.uk/government/publications/entering-the-uk-as-the-holder-of-an-article-10-residence-card/entering-the-uk-as-the-holder-of-an-article-10-residence-card) recommends bringing separate documentation for your relation to the union citizen _in addition to_ the article 10 card.

In principle you can just show up at the UK border and ask to be let in based on _any_ convincing evidence that you're a family member of the union citizen you're traveling with -- such as a marriage certificate -- and they have to consider this evidence rather deny you entry immediately. But this can easily take hours and quite ruin the beginning of your holiday. And that's assuming that you even make it to the border, because without an article 10 card you probably won't be allowed to board a plane towards the UK. So this only works if you go by train from France or Belgium (in which case delays at immigration will make you miss your train unless you plan for them and arrive hours in advance).

The sane thing for you to do is to [apply for an EEA family permit](https://www.gov.uk/family-permit) (or its Irish equivalent, depending on where you're going) before leaving.