"Vegetable is a culinary term. Its definition has no scientific value and is somewhat arbitrary and subjective. All parts of herbaceous plants eaten as food by humans, whole or in part, are generally considered vegetables. Mushrooms, though belonging to the biological kingdom, fungi, are also commonly considered vegetablesâ¦Since 'vegetable' is not a botanical term, there is no contradiction in referring to a plant part as a fruit while also being considered a vegetable. Given this general rule of thumb, vegetables can include leaves (lettuce), stems (asparagus), roots (carrots), flowers (broccoli), bulbs (garlic), seeds (peas and beans) and of course the botanical fruits like cucumbers, squash, pumpkins, and capsicums.
Thats straight from http://wiki.answers.com/Q/Are_cucumbers_vegetables_or_fruit
1) If it tastes sweet, it's a fruit. Cucumbers and tomatoes are vegetables because they don't taste sweet.
2) If it is the part of the plant that has seeds in it, it is a fruit. Both tomatoes and cucumbers are fruit according to that definition.
So it really depends on how you want to look at it. But technically a tomato is a fruit.
And now I'm gonna lock this thread because you make short posts either disagreeing or agreeing or repeating something someone else already said. >_> For more info about it, try Wikipedia.org or use a search engine to find information.