small and not making much difference to something► small · I want to make a few small changes to the design.· There is still one small problem that we haven't dealt with.· Government statistics showed a small drop in the annual rate of inflation.
► slight small and not very important or not very noticeable: · There has been a slight change of plan.· The doctor says there has been a slight improvement in her condition.· He was a good friend - always available to help at the slightest sign of need.not the slightest (=none at all): · Tom? I haven't the slightest idea where he is.· US foreign policy at the time hadn't made the slightest difference in the situation.
► minor not important enough or serious enough to worry about: · She fell off her horse, but suffered only minor injuries.· The contract seems fine, except for a few minor details.· With one or two minor changes, the course is the same as last year.
► infinitesimal an infinitesimal amount, risk etc is so small that it makes very little difference or is not worth worrying about: · Even an infinitesimal change in temperature will be recorded by the equipment.· I'd say the chances of your catching the disease are infinitesimal.
► tiny extremely small: · I've made one or two tiny alterations, but otherwise the house is the same as when I bought it.· There's been a tiny decrease in the number of people out of work.
► minute a change or difference that is minute is so small that it is difficult to see it or notice any effects resulting from it: · The equipment records minute changes in air pressure.
extremely small SYN minuscule: 
infinitesimal changes in temperature—infinitesimally adverb: