Abstract Apart from Tamil, Malayalam is the only Dravidian language that still retains a fifth liquid in its inventory (denoted as /ʐ/), a sound that can be traced back to Proto-Dravidian. The phonetic and phonological status of this sound has been the subject of considerable debate, both in terms of its rhotic versus lateral status and its phonetic realisation. Studies to date have been impressionistic, so this is the first acoustic study of all five liquids in Malayalam. Production data from 8 male speakers reveal that while /ʐ/ is realised as a central post-alveolar approximant, its ambiguous phonotactic patterning and mixed acoustic profile are contributors to its mixed identity. An understanding of the complex patterning of this sound, which straddles the rhotic/lateral divide, requires an appreciation of the role of secondary acoustic resonance in distinguishing members of a crowded liquid system and in preventing a /ʐ/-/ɭ/ merger.