The term "lash up" has various synonyms that convey different shades of meaning. Some of the common words that can be used as synonyms for "lash up" include improvise, jerry-rig, jury-rig, cobble together, make-shift, and kludge. These words denote a temporary or makeshift solution to a problem, often involving unconventional methods. Other synonyms for "lash up" include concoct, contrive, devise, engineer, fabricate, and construct. These words imply a more deliberate and planned effort to create something, but may still have the connotation of being somewhat makeshift or temporary. Overall, these synonyms suggest an approach to problem-solving that emphasizes resourcefulness and ingenuity, often in the absence of more formal or traditional solutions.