'informally-organized' originates from the combination of 'informal' and 'organized', where 'informal' means 'not formal' and 'organized' means 'arranged in a systematic way'.

'Informally-organized' combines the words 'informal' and 'organized', which have been used in English since the 16th and 17th centuries respectively.

Initially, 'informal' meant 'not according to the usual rules', and 'organized' meant 'arranged systematically'. Together, they convey a sense of casual arrangement.