(idiomatic) One will find what one is looking for under an obvious sign for it.

(literally) A mark, such as a line of seaweed, showing the highest level reached by a body of water.

(idiomatic) Listen to me; used before a statement one wishes to emphasize, especially a prediction.

(idiomatic) To make, or leave, a lasting impression, especially to achieve prominent success. / To sign (a document) by making a cross or other mark.

plural of long-vowel mark

The symbol ː (the triangular colon), which marks long vowels in IPA. / The symbol ー, which marks long vowels in Japanese hiragana and katakana.

The punctuation mark "¿", which is placed at the beginning of questions in Spanish and, less commonly, Catalan.

plural of inverted question mark

(idiomatic, sports) fast to act or react

(computing) A character indicating the endianness of a string of text; specifically, the Unicode character U+FEFF ZERO WIDTH NO-BREAK SPACE.