sāi / sài /
verb HSK 6 #1,601

Meanings

  1. 1 to plug; to stuff; to block up
  2. 2 to squeeze in; to cram
  3. 3 stopper; cork; plug

Examples

瓶口
Bǎ píngkǒu sāi zhù.
Plug up the bottle opening.
Bié zài wǎng shūbāo lǐ sāi dōngxi le.
Stop stuffing things into the backpack.
Tā bǎ qián sāi jìn kǒudài lǐ.
He stuffed the money into his pocket.

Tips

usage
has three readings: sāi for everyday stuffing and plugging (塞车, 塞子, 耳塞); sài for frontier fortress (要塞, 塞翁失马); sè for literary block (堵塞, 敷衍塞责). sāi is by far the most common in speech.
register
塞车 (traffic jam) is the standard term in Hong Kong, Taiwan, and southern Mandarin; northern speakers usually say 堵车 instead. Both are understood everywhere but mark regional flavor.

Components

radical
earth; ground
Bottom earth radical — the indexing radical. Earth is the floor of the container, the foundation that makes the stuffing possible. Also grounds the alternate sài reading (要塞 frontier fortress) — an earthwork blocking a strategic pass. Same family: block, fill in, bury.
semantic
mián
roof; cover
Top roof radical — sets the enclosed-space scene. Plugging and stuffing happen inside something: a bottle, a bag, a doorway, a fortress. The roof on top of marks the bounded interior into which things get crammed. The whole char is indexed under Kangxi #32 — the soil at the base.
semantic
gōng
work; tool (here graphic)
Middle 7-stroke unit — visually a fused with two pairs of crossing strokes, originally a graph of bricks packed tightly between supports. Standalone is 3 strokes; here it has absorbed the bundling pattern into a single fused unit. The picture: stuff jammed between roof and earth — the 'cramming, stuffing, blocking' core.

Stroke Order

sāi