I used to teach a lesson on English expressions for describing the world as we perceive it through our 5 physical senses. In other words, how to convey what we see, hear, smell, taste, and feel. The difference between hear and listen to (both 聞くin Japanese), the distinction between look at and watch (見るor 観るin Japanese, both of which are pronounced miru, I believe).
ワキガ came up in the smell section. Below is an excerpt from the handout that I made for my students:
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Smell / Scent / Odor/ Stench / Aroma/ Fragrance
The word scent is generally neutral. People and animals all have scents. Dogs can follow people or other animals by the scent left behind.
The word smell is neutral and can be used to describe pleasant and unpleasant things, but be careful—if you say, “S/he smells,” or “It smells in here,” it sounds negative. However, if you’re specific, e.g. “It smells like apples in here,” or “It smells like fish,” the word smell is neutral and only describes apples, fish, etc.
The word odor can be used to describe neutral smells, but it often sounds negative. An example is the phrase “body odor,” which describes the smell that people acquire when they perspire (sweat) a lot.
Stench is always an unpleasant odor.
Aroma and fragrance are used to describe pleasant smells. Fragrance usually implies a sweet smell, such as flowers or perfume. However, if you say someone has a “strong or powerful fragrance,” it might sound negative, as if s/he is wearing too much perfume or cologne.
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In distinguishing nuances, I felt certain in saying that fragrance and aroma have pleasant connotations, and that stench is always bad. And then, to me at least, smell and odor are neutral. They can be good or bad. Although I have to note that I'd probably never say, "That is a nice odor" or "I love that odor." However, dictionary.com defines the word as possibly being agreeable or unpleasant, and I will not argue with dictionary.com.
But one usage of odor, I would say, is always negative: body odor, or B.O. "You have B.O." is never a compliment; it means you need a bath. In the midst of my explanation, a student cried out 「ワキガ!」 There was much laughter in the room. This is how I learned the colloquialism.
I've been debating in my mind as to whether I should mention the name of my school...
Okay, it was Gakushuin Women's College (学習院女子大学). I mention this because, to me, it adds a wonderfully ironic element to this memory. Gakushuin is an educational institution which was, according to Wikipedia, "originally established to educate the children of Japan's nobility." For this reason, especially with the women's university, a reputation exists in the minds of some, perhaps of many. Back when I used to teach business people, every middle-aged salaryman thought of Gakushuin women (学習院女子) as お嬢様, or princess-like ladies. (I would like to note that, as is true just about anywhere, there are all kinds of people attending the college.)
I will never forget that a 学習院女子 taught me the word ワキガ. I love that school.
Some ワキガ videos!
https://www.youtube.com/watch?v=NogKY9nEh0c
https://www.youtube.com/watch?v=qnyITFq8se8
https://www.youtube.com/watch?v=4_1FvpmLwRM
