noun
young pine tree
Refers to a pine tree that is still young and small, often used in gardening or poetic contexts.
庭に若松を植えた。
I planted a young pine tree in the garden.
玄関に若松を飾る。
We decorate the entrance with a New Year's pine arrangement.
門松 is a larger, paired pine-and-bamboo decoration placed at gates or entrances, while 若松 specifically refers to the young pine component or a simpler pine-only decoration.
Compound of 若 (waka, 'young') and 松 (matsu, 'pine'). The New Year decoration sense derives from the use of young pine branches as auspicious symbols.