>there *should be a word for this! Hurry up tsuwm, or there will be...

sorry, this looked like a food thread you know...

Jackie is right; this is baby talk, by extension:
1 a : the syntactically imperfect speech or phonetically modified forms used by small children learning to talk b : the consciously imperfect or altered speech used by adults in speaking to small children 2 : oversimplified speech or writing [MWCD]

caradea is also right; the original, obsolete sense of lallation is "Childish utterance". [OED]

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