Broad katakana noun for a line: a drawn line, boundary line, design line, or similar linear mark or concept. In many literal contexts, 線 is the more native-looking equivalent.
I drew lines on the court.
I drew a straight line on the paper.
Please do not cross this line.
彼の発言は明らかにラインを越えている。
His remark clearly crossed the line.
This dress has beautiful lines.
The design follows the line of the car body.
ＬＩＮＥ is the trademarked messaging app, while ライン (written in katakana) usually means a physical line, queue, or production line and is unrelated.
lineup; range of products; list of players or performers
guideline
pipeline
skyline; city skyline · scenic mountain road; mountain ridge road
starting line; start line · starting point
essential utilities; critical infrastructure · lifeline; vital connection
hotline; hot line
borderline; boundary line
inline; in-line
Written phonologically in katakana; no kanji form or detailed language-of-origin information is specified.
airline
eyeliner
deadline
underline
linebacker
tagline; tag line
by-line
picket line
hemline
line-marking machine; line painter
lineman
linemen
line-marking machine; line marker
line organization
crossing the line; going too far