にわか (にわか, niwaka) is a Japanese slang word that means “a newbie” in a disapproving way. It is often used to criticise pretentious people who behave as if they have copious knowledge and experience about something, even though they’ve known it for a very short period of time.
One common phrase using にわか is “にわかファン” (niwaka fan), which means “a bandwagon fan” and describes a person who supports a particular team or person after they have become popular or trendy. For instance, every time the FIFA world cup comes around, you see a plethora of “にわかサッカーファン (niwaka soccer fans)” popping up out of nowhere and expressing their “passion” for 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” is a common expression that literally means “I cannot believe it immediately”, that is, “I find it hard to believe”. The word “にわか雨” (niwaka ame) is also a common word, which 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 used in a self-deprecating way.
Newbies in strength training often talk about the importance to take 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)