にわか (にわか, niwaka) is a Japanese slang word that describes newbies in a negative way. It is often used to criticise pretentious beginners who behave as if they have a lot of knowledge and experience about what they started a couple of weeks/months ago. One of the most common phrases is “にわかファン” (niwaka fan), meaning “a bandwagon fan”, who supports a particular team or person as soon as they have become popular or trendy. For instance, every time the FIFA world cup comes around, you see a sea of “にわかサッカーファン (niwaka soccer fan)” popping up out of nowhere and expressing their “passion” about football.
Generally, にわか (niwaka) is used as an adverb “にわかに” (niwaka ni) meaning “suddenly” or “immediately”. For instance, “にわかには信じがたい” (niwaka ni ha shinji gatai) is a common expression that literally means “I cannot believe it immediately”, that is, “I find it hard to believe”. Also, the word “にわか雨” (niwaka ame) is a common word, that literally means “sudden rain” and indicates rain that falls suddenly. See the link below for a variety of Japanese words related to 雨.
(note) As in this example, にわか is also often used as a mean of self-deprecation.
Niwaka of weight training often rambles on how important it is to drink protein.
After having won the tournament, the team suddenly got a lot of attention.
Synonyms: 初心者 (beginner)、新参 (newcomer)
Synonyms in English: beginner, newbie, bandwagon fan
Related words and phrases: にわか雨 (rain shower)