Chemical element; typically written in katakana as リン.
リンは肥料の重要な成分です。
Phosphorus is an important component of fertilizer.
matchbox label
phosphate rock; phosphoric ore
white phosphorus
Katakana spelling is standard for this chemical element; the kanji form 燐 is rare and not commonly used.
Kanji form is rare and mostly encountered in older scientific or literary contexts.
From English 'phosphorus', via scientific terminology.