noun
small notepad; short letter pad
A small pad of paper for writing brief notes or short letters, often used for thank-you messages or quick correspondence.
お礼の言葉を一筆箋に書いた。
I wrote a thank-you note on a small notepad.
一筆箋はちょっとしたメッセージを送るのに便利だ。
A small notepad is handy for sending brief messages.
メモ帳 is a general memo pad, whereas 一筆箋 often implies a slightly more formal or decorative pad for short personal correspondence.
Compound of 一筆 (ippitsu, 'one stroke' or 'a brief note') and 箋 (sen, 'paper' or 'slip'). The term describes a pad for writing short, single-stroke-like messages.