This word was very popular in and around the Washington DC area. I first heard the word circa 1985 in high school. Veriable definition. Could be crazy, high, insane, tripping, pissed or thousands of other meaning. Definition is dependent upon the context. Example

D.C. Metro area term for being absurd, ridiculous, or idiotic.

i.e. out to lunch

Michael Riversongs cat

food you eat at noon

The act of bullshiting or wasting time.

lənch

1. Also known as a nooner or a “boat ride” (during which a boat ride may or may not occur), but always a mid-day sexual encounter with your significant other. Not to be confused with afternoon delight which always occurs after LUNCH.

2. “LUNCH” is an intimate gathering of gentlemen who meet to eat and drink mid-day, not to be confused with “lunch”. The number of gentlemen must exceed three men and has no upper limit other than the size of the table.

Often LUNCH has no set menu, nor is it prix fix. The most exclusive LUNCH gatherings have menus established by the chef under the “carte blanche” rule of Michelin dining.

LUNCH must include multiple bottles and types of liquor. Bonus LUNCH points are accrued for flaming drinks. Some expert arbiters of LUNCH actually cook and eat their own lunches in the restaurant’s kitchen, in which case the number of attendees may fall below two people, and may only occur if the acumen is judged high enough by the executive chef.

LUNCH may not last less than 1.5 minutes (a.k.a. Lunchus Minoris) nor exceed 6.5 hours (a.k.a. Lunchus Majoris nee Cazadores Primerus Majorus).

Synonym for marihuana.

Lunching - Gerund: Washington D.C. term meaning that someone is acting stupid or lame. Similar to "out to lunch". Also, "lunchin'" or noun, "lunch box"

1. The second meal of the day, except for college students where it's the first meal of the day.
2. The mid-day break from the work place (usually 60 minutes), though sometimes used for work-related social interactions.
3. (out to ~) crazy