Uum, that's like asking if it's possible to think without thing. But if you mean it another way, it is possible to flirt without being detected through words or speech. It's all about using body language and it is subtle enough to brush and dismiss the flirting as nothing. Firstly, fleeting eye contact is very important when discreetly flirting. Smiling a lot and acting happy and coy in front of the person might help too.
Sometimes when you compliment someone like a coworker, especially on their looks, they might take it the wrong way and think that you are hitting on them... Such is life, there's no such thing as giving compliments as form of goodwill anymore, because everyone thinks that we have an agenda.
So yes, it can be possible, especially when you are unknowingly doing the flirting.
It is possible, by being very subtle in your technique. Smile and show your interest but in a very low key way. The best way to win someone’s interest is to get and hold their attention by demonstrating your sincere desire in getting to know who they really are. The way to truly do this is to ask a good lead in open-ended question that will get them talking about who they are. From there gradually get deeper with the questions, being sure to keep periodic and steady eye contact throughout the conversation. Then toward the end gently touch her or his hand then let go. If you show genuine sincere interest in someone else it can be flirting.
I'm with the Diva on this one ;-) It’s very possible to flirt without flirting; it’s something everyone does to varying degrees on a daily basis without realizing it. Flirting at its very core is to amuse another person. Although most people would reserve the word for when they are describing interactions with their significant other, or potential significant other, it still applies to regular interactions at school, at the office or at the store. For example, at school it’s very common to flirt with your peers. Often in a group of men there is always that one guy who is witty and can talk about any subject to anyone. That guy is often associated as being flirty but really, all he’s really doing is amusing others. In the office people tell jokes and amuse others for the sake of building bonds and having a good time. Before you know it their supervisors are fond of them not just because of their hard work but because they find them amusing. This was made possible with all those instances when flirting occurred without the two knowing it. It’s flirting without realizing its flirting. People who often engage their cashier at the store are flirting. People try to amuse their cashier as the cashier scans our food so it’s not so awkwardly silent. Or vice versa, a good cashier is often associated for being able to amuse us in those two minutes they are assisting us. Flirting happens.
I don't think it is. Some people do tend to take what you say and how you say certain things as flirting, even though that was not your intention. I think it comes down to perception and how people see and take your actions and words. Or I guess you may not be aware that you're doing that, even though I really don't think that it's likely.