Leet speak for Bitcoin accidentally coined by a 94-year-old grandmother and possibly the oldest known Bitcoin investor on October 29, 2013.
Also spelled, ฿low Stamp.
My 94 year old grandmother gave me $1000 dollars last year to buy her some Bitcoins. Today she asked me how her "blow stamps" were doing. She's probably the oldest owner of Bitcoins in the world, and she's sitting on $20,000 worth.