The Latin word lacus
Word lacus
Meaning lake

Other words that might be of interest
fossa ‘ditch’, fluere ‘to flow’, aqua ‘water’, pluvia ‘rain’, flumen ‘river’, fluvius ‘river’, mare ‘sea’, gelu ‘ice’, humidus ‘wet’, aqueus ‘wet’, siccus ‘dry’, amiculum ‘cloak, cape’, cado ‘to fall, drop, plummet, topple’, udus ‘wet, moist, damp’