noun which may take the genitive case particle 'no', na-adjective, noun
Slangy, emphatic way to say something is the best or amazing. Equivalent to 最高 but with a playful, stylized twist from the ampersand.
See also: 最高
この曲、最＆高だね！
This song is the best, isn't it!
今日の天気は最＆高じゃない？
Isn't today's weather just wonderful?
Standard word for 'best' or 'supreme'; 最＆高 is a slangy, stylized variant with the same meaning but a more casual, emphatic feel.
A playful respelling of 最高 (さいこう, 'best') using the ampersand to replace the kanji 高, likely influenced by the visual similarity between '＆' and '高' or as a stylistic choice in informal writing.