Filmy and flimsy are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary, but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted, or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
Filmy (pronounced “fihlm-mee”) is an adjective. It means cloudy, dirty, or hard to see through. For example, it might describe dirty windows, lenses, or other normally clear or transparent objects. Figuratively, it describes something being clouded, obscured, or hard to understand.
Flimsy (pronounced “flihm-see”) is an adjective. It describes something that is literally weak, or collapses under pressure. Figuratively, it describes something more abstract that doesn’t hold up, like an alibi, or an argument.
The following story uses both words correctly:
Flicka asked her son Fleming to take out the trash and clean the windows when he got home from school.
When she arrived home at dusk, the windows were still filmy, and the trash was still overflowing. “Um, Fleming? Why haven’t you done what I asked?” she asked.
“I have too much homework. I’m so stressed right now.” he said. He sounded like he was reading badly off a cue card. Clearly he was distracted. She could hear laser gun sounds coming from his room.
“Oh really? That’s a flimsy excuse, young man. Do you think I can’t hear video game noises coming from your bedroom?!”
“I’m just decompressing after school, Mom. I will get right on it.”
“School ended four hours ago. Turn the TV and the console off right now, or I’m taking them. Do your chores. Then get on that homework.” she said authoritatively.