Not in the regular, usual, or established form; not according to official, conventional, prescribed, or customary forms or rules; irregular; hence, without ceremony; as, an informal writting, proceeding, or visit.
We must ensure that while eliminating child labor in the export industry, we are also eliminating their labour from the informal sector, which is more invisible to public scrutiny - and thus leaves the children more open to abuse and exploitation. Carol Bellamy
During a large disaster, like Hurricane Katrina, warnings get hopelessly jumbled. The truth is that, for warnings to work, it's not enough for them to be delivered. They must also overcome that human tendency to pause; they must trigger a series of effective actions, mobilizing the informal networks that we depend on in a crisis. Gary Wolf
Judging by informal observation, most young Americans burn up their spare time buffing their emotional IQ and self-esteem with social media and non-stop texting. That's great for eye-thumb coordination, but what about the satisfaction of actually making something? Seth Shostak
On many occasions, an informal buffet and casual seating offer a little more intimacy than a loud gathering around a big table. Yotam Ottolenghi
Email is very informal, a memo. But I find that not signing off or not having a salutation bothers me. Judith Martin