1. accept an offer or invitation
take someone up on an offer
o 'take someone up on something' means to avail of or accept an offer. You can tell someone you would like to take them up on their offer to help you for example or take them up on an invitation. To take someone up on something can also mean to ask someone to explain something or discuss something they have said or done in order to make themselves more clear or because you found what they said strange or you didn't understand. So for example, if someone says something unusual in a meeting or something that doesn't sound correct you can say, "I'd like to take you up on that point because that information doesn't sound correct to me."