甘 is literary for 'sweet'. In modern speech, 甜 (tián) is used instead. 甘 survives in set phrases like 甘心 (willing), 甘苦 (sweetness and bitterness).
Components
ideograph
甘gān
sweet
Abstract indicator: a 口 silhouette with a small horizontal bar inside marking where sweet flavour is held on the tongue. Unlike 口 (open mouth) and 曰 (speaking mouth), 甘 uses the inner mark as a positional cue for savouring. Kangxi radical 99, heading 甘甜, 甘愿, 甘苦.
Radical
SweetKangxi #99
A small radical group with very low productivity. The most useful compound is 甜 (sweet), which writes 甘 alongside 舌 (tongue). The shape pictures a mouth holding a morsel — what stays in the mouth tends to be tasty, hence 'sweet'.