What does attic mean in slang?

In slang, attic has several meanings, most commonly referring to head or mind, as in attic meaning top part of house used metaphorically for head where thoughts are stored. For example, saying he has an attic full of useless facts means his mind is full. In older slang, attic can mean head, as in use your attic meaning think. In some drug slang, attic can refer to being high, though less common. In British slang, attic can mean drunk or tipsy. In some contexts, attic can refer to mental state, like he's a little off in the attic meaning mentally unstable or eccentric, similar to saying not right in head. In construction slang, attic can mean top floor party or hidden space. For example, phrase in some regions, attic party means secret gathering. In general slang, attic is metaphor for mind because attic is top storage of house, similar to brain storing memories. So slang meaning of attic is head, mind, or mental space, often used in phrases like clear out your attic meaning organize thoughts, or someone is weak in the attic meaning not intelligent. It can also mean upper room for storage used metaphorically for keeping secrets. So attic in slang most commonly means head or mind, with expressions about being off in attic meaning crazy or eccentric.