IPA: /ˌʌn.kənˈtroʊ.ə.bli/
KK: /ʌnˌkɒntrəˈloʊbli/
In a way that cannot be controlled or managed; acting without restraint.
She laughed uncontrollably at the funny joke.
Uncontrollably → It is formed from "un-" (meaning not), "control" (from Latin "contrarotulare", meaning to check or regulate), and "-ably" (meaning in a manner). The word "uncontrollably" means in a manner that cannot be checked or regulated.
Think of 'not' ('un-') being able to 'regulate' ('control') something, which helps you remember that 'uncontrollably' means acting in a way that cannot be controlled.