形容詞 indelible:

1. cannot be removed, washed away or erased
   同義詞：unerasable

1. An indelible pen for labeling clothing.
   一種為衣物作標(biāo)簽用的其筆跡很難去掉的筆
2. Act promptly to remove spots from these fabrics. The longer you delay, the more indelible will the mark become.
   趕快動(dòng)手把這些污點(diǎn)從這些織物上擦掉。拖延時(shí)間越長(zhǎng)，就越難擦掉。
3. His concern for the masses made an indelible impression on us.
   他對(duì)群眾的關(guān)懷給我們留下不可磨滅的印象。

in.del.i.ble

adj.（形容詞）
Impossible to remove, erase, or wash away; permanent:
不能消除的，擦不掉的：不能去掉、擦掉或洗掉的；永久的：
例句：
indelible ink.
去不掉的墨漬

Making a mark not easily erased or washed away:
污點(diǎn)無(wú)法抹掉的，難忘的，永久的：做出不易去除或洗掉的痕跡的：
例句：
an indelible pen for labeling clothing.
一種為衣物作標(biāo)簽用的其筆跡很難去掉的筆

來(lái)源：
Latin indôlôbilis
拉丁語(yǔ) indôlôbilis
in- [not] * see in-
in- [不] *參見(jiàn) in-
dôlôbilis [capable of being effaced] from dôlôre [to wipe out]
dôlôbilis [能被抹去的] 源自 dôlôre [抹去]

【引伸】
indel.ibil.ity 或
indel.ibleness
n.（名詞）
indel.ibly
adv.（副詞）