An odor, aroma, scent, stench, or smell were factors determined by the olfactory senses. Odor given off by a person or animal's body was identified as body odor or, as well, scent.
In 2154, Jonathan Archer told Trip Tucker to change his uniform before he stunk up the place. (ENT: "Babel One")
In 2364, despite the holographic Minuet being a computer-generated image, her smell was one of her aspects which seemed so real to William T. Riker. (TNG: "11001001")
In 2366, when giving Geordi La Forge advice on pursuing women, he told him that words come later and that it is the scent that first speaks of love. (TNG: "Transfigurations")
Following his marriage to Keiko in 2367, Miles O'Brien told her of the foods he grew up on, and how he could "still remember the aromas when my mother was cooking." (TNG: "The Wounded")
In 2370, when Talur mistook Data for an "ice man", she noted that his breath did not have a smell. (TNG: "Thine Own Self")
According to Romulan Senator Vreenak, while tasting the replicated kali-fal offer to him by Captain Benjamin Sisko in 2374, it was a "fair approximation," but that it was "somewhat lacking in aroma," as "real kali-fal should forcibly open one's sinuses well before the first sip." As they continued to talk, Vreenak took another sip, and reassessed his original statement as an analogy to Sisko's arguement as to why the Romulan Star Empire should become allies with the Federation, stating, "It really is a good replica. The aroma's starting to grow on me. For a moment there I almost forgot that it wasn't the real thing, but only for a moment." (DS9: "In the Pale Moonlight")
According to The Doctor, in rare cases external stimuli such as aromas, touch, and voices have triggered a response from a comatose patient. He noted this to Neelix after Tuvok attacked by a Ba'Neth intruder aboard the Delta Flyer. Neelix took this to mean that "if I stay here and, and try to talk to Tuvok, I might be able to provoke some sort of response?" The Doctor concurred, "If anyone can provoke Tuvok, Mister Neelix, it's you." (VOY: "Riddles")
Neelix used a similar tactic with the amnesiac B'Elanna Torres, by preparing for her her favorite breakfast: pancakes with maple syrup. She noted that they "smell[ed] good", whereas Neelix had hoped that "You know, sometimes food is like time travel. You inhale an aroma, take a bite of something and suddenly, bam! You're back at the moment you first tasted it." His hopes were ultimately unsuccessful, however, as she tasted them, she described that "They're good. I'm not experiencing time travel." (VOY: "Workforce")