year-end, age, occasion, opportunity
歳 centers on the passage of time, especially the turning of a year. It marks age (years lived), year-end, and by extension occasions or opportunities that come with the cycle of years.
歳 originally combined 步 (step) with 戌 (a halberd-like weapon), representing the annual cycle of harvest and ritual. The modern form simplifies the lower part to 戌 enclosing 小, but the core idea of a yearly cycle remains.
The top 止 (stop) and the outer 戌 (like a weapon) enclosing 小 (small) suggest a small pause in the yearly cycle: a year-end occasion to stop and reflect on age and opportunities.
For サイ, imagine a sigh (サイ) at the end of the year as you count your age: sigh -> サイ, and the year-end occasion makes you sigh.
... years old; age (of) ...
banzai; hurray; hurrah; hooray
thousand years; millennium; eternity
time; years
annual revenue (government); annual income (government); budget receipts
annual expenditure (of a state, organization, etc.)
year-end gift
twenty years
matter for great congratulation
almanac of seasonal words (for haiku poets)
annual expenditure
year end
door-to-door manzai; form of comedy originally performed at people's homes by entertainers during the New Year festivities; precursor to modern day manzai
under 1 year old (of a baby); 0 years old
20 years old
year-end gift
child under a year old
prenatal period (of a baby's development); period when a baby is in the womb
general account expenditure
general expenditures; general spending