Masamune is almost certainly the romaji rendering of a name, probably 正宗 which is a compound of "righteous" and "essence, religion, sect." I guess this because I know there is a manga artist with this name which must be why you ask. Strictly speaking, unless you know the kanji used the meaning is uncertain. Names are just that, anyway.
To spell a Japanese word with English letters is called Romaji. The word legendary in Romaji is: denkiteki.
shin ju means to make love and/ or anal sex
Volcano in Japanese is 火山. These are kanji symbols meaning: 火-fire and 山-mountain. In romaji form the word is Kazan.
Lava in Romaji Japanese can be:Kazangan - meaning volcanic rock or lava. It is pronounced: Kah - zahn - gahnor:Yougan - meaning lava sack/lava.
The romaji for it is "uta". (うた/歌)
カメレオン (Kanji)Kamereon (Romaji)
I believe the Japanese word is キャスト (kya-su-to) which is Cast is English. If this does not work with your text from which you got the romaji or the sentence does not make sense then perhaps you misspelled the romaji. Remember that lines over vowels makes longer vowels, which can change a words meaning entirely.
It's called 'Romanization' when a Japanese word is written in English letters, and the word is called Romaji. So the romaji for 'sweetness' is 'amasa' and 'amami' means 'sugary/sweet flavor, sweetness'.
Romaji: Kata Kana: かた Kanji: 肩
The Romaji :Sukūtā (Soo-koo-taah)The Katakana: スクーター
'Sadistic' in Japanese [Katakana] is: サディスティック In Romaji (English Pronuniation), this reads: Sadesuteku
According to both a Japanese to English dictionary and a Romaji to English website (which I know to be extremely accurate), it's not a Japanese term. The website said "not found", and the closest word in the dictionary was "tomodachi", meaning pal or friend in the reference meaning, as in, "Hey, pal." or "Hello, friends."