ear of rice; head of a rice plant; spike
Refers specifically to the grain-bearing part at the top of a rice stalk. Used in agricultural contexts.
穂首が黄金色に実っている。
The ears of rice are ripening to a golden color.
Compound of 穂 (ho, 'ear of grain') and 首 (kubi, 'neck'), referring to the neck-like part of the rice plant that bears the grain. The reading ほくび is a straightforward combination of the two elements.