Memphre means: A large aquatic creature, similar to the Loch Ness monster, which supposedly lives in Lake Memphremagog, Quebec, Canada.. It is crypto-trading vocabulary; common on X, Discord servers, and trading-Telegram groups your teen may follow. There is no real cause for parental concern; it is descriptive vocabulary rather than risky behaviour. If your teen uses it, context will usually make the intent clear. A short, curious question about where they heard it is usually all that is needed to know whether to follow up.