Everyone has their own definition of "wealthy." Some say it's $1 million, others say $100 million. Some say it means making more than your brother-in-law. Others say it means not having to work or having strong relationships with family and friends.

But a new survey from UBS shows that most investors say "wealthy" means $5 million—with at least $1 million of that in cold, hard cash.

The UBS Investor Watch asked 4,450 investors if they consider themselves wealthy. Fully 60 percent of those worth $5 million or more said they're wealthy, while only 28 percent of those worth $1 million to $5 million said they were wealthy (those were the only two categories given).

(Read more: Top 1% control 39% of world's wealth)

Half of the respondents said that, more broadly, being wealthy means having "no financial constraints on activities." Only 16 percent said it meant "surpassing a certain asset threshold" and 10 percent said it means "not having to work again."