Uno scrupolo (a scruple) is a noun in Italian that has a cognate in English, as we see. So there is a connection, but in Italian, this word is more than just its cognate.
What do we mean by this? Let’s look at the English first.
Someone has scruples when he or she tries to do the right thing, morally. A scrupulous person is conscientious, cautious, careful, circumspect; exacting or rigorous.
These definitions apply in Italian as well.
Lei, invece, è un truffatore senza scrupoli che cerca di approfittare di lui.
You, on the other hand, are a conman without scruples who is looking to take advantage of him.
Caption 39, Questione di Karma - Rai Cinema - Part 11Play Caption
Gli dici che non ruberai mai un taxi in vita tua, ma per le altre macchine non ti fai troppi scrupoli.
Tell him that you will never steal a taxi your whole life long, but for other kinds of cars you won't have too many scruples.
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Marika uses the adjective form scrupoloso (scrupulous) in describing the characteristics of someone born under the sun sign Vergine (Virgo).
Cerchi sempre il pelo nell'uovo e sei perfino capace di trovarlo, attenta e scrupolosa come sei.
You always look for the hair in the egg (you split hairs), and you're even capable of finding it, careful and conscientious as you are.
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However, the noun scrupolo can also be used when someone has a concern about something, a doubt, a qualm. In Italian, it is very common. It comes down to being conscientious and careful.
Senta, magari è inutile. È uno scrupolo...
Listen, maybe it's not useful. It's a qualm...
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Eva, fidati, assaggia. Solo per scrupolo.
Eva, trust me, taste. Just to make sure.
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So, when you have proofread a letter a thousand times, you might read it one last time, per scrupolo.
Before putting a dish on the table, you taste it for the salt, solo per scrupolo.
Did you turn off headlights on the car? I’ll check, per scrupolo.
Per scrupolo is a nice way of saying you want to double check something: just to make sure.