I don't have any problem saying it's torture. Here's the definition, per dictionary.com:

tor⋅ture
  /ˈtɔrtʃər/ Show Spelled Pronunciation [tawr-cher] Show IPA noun, verb, -tured, -tur⋅ing.
Use torture in a Sentence
–noun
1. the act of inflicting excruciating pain, as punishment or revenge, as a means of getting a confession or information, or for sheer cruelty.
2. a method of inflicting such pain.
3. Often, tortures. the pain or suffering caused or undergone.
4. extreme anguish of body or mind; agony.
5. a cause of severe pain or anguish.

Waterboarding is a tool of torture, and I do think torture has its place. We're talking about hardened prisoners who have life or death information that they are unwilling to share here. Is it pretty? No. Is it a helpful method to employ sometimes? Sure. If innocent lives depend on getting information out of the mind of an uncooperative, unrepentant criminal who has been unwilling to share that information through any other means, do I think we should refrain from scaring them with consequenceless but extremely terrifying waterboarding just so we can say we're nicer? Ummm... no.