adv
Uncommon
sid
ehs-eye-dee
Sid (adv) means In prescriptions, an abbreviation meaning "once a day" (from Latin semel in die), used for how often a medicine should be taken. Example: “The label read "500mg sid" meaning one dose every day.”
adv
1
In prescriptions, an abbreviation meaning "once a day" (from Latin semel in die), used for how often a medicine should be taken.
"The label read "500mg sid" meaning one dose every day."
"The vet prescribed the tablets sid for two weeks."
How to use sid
Learner’s notesIn plain EnglishA medical shorthand on prescriptions meaning the medicine is taken once every day.
Common mistake
Don't confuse with "bid" (twice a day) or "tid" (three times a day) — similar-looking prescription abbreviations with different meanings.
When to use it
Used almost exclusively in clinical or veterinary prescription notes, not everyday speech.
Easily confused with
bid →
tid
Vocabulary Flow
Build your vocabulary from words like sid.
Vocabulary Flow serves the next word, and the next — meaning, pronunciation and an example each time. Practice at your level, or learn English in your own language.
Start vocabulary practice
Fill the gap
Can you complete this real example?
The label read "500mg _____" meaning one dose every day.
Etymology
Shortened from sidiki or sidiqi.
Frequently asked questions
What does “sid” mean?
The word “sid” means in prescriptions, an abbreviation meaning "once a day" (from Latin semel in die), used for how often a medicine should be taken. In plain terms, a medical shorthand on prescriptions meaning the medicine is taken once every day.
How do you pronounce “sid”?
“Sid” is pronounced ehs-eye-dee (/ɛs aɪ diː/ in IPA).
How do you use “sid” in a sentence?
Here is “sid” used in a sentence: “The label read "500mg sid" meaning one dose every day.”
What part of speech is “sid”?
“Sid” is an adverb.
Is “sid” a common word?
“Sid” is an uncommon word in modern English.
What does "sid" stand for on a prescription?
On a prescription, "sid" is an abbreviation meaning "once a day," derived from the Latin phrase "semel in die." It tells a patient or pharmacist how often a medicine should be taken.
What is the difference between "sid" and "bid" on a prescription?
"Sid" means a medicine should be taken once a day, while "bid" means it should be taken twice a day. Both are Latin-derived abbreviations used in prescription dosing instructions.
Is "sid" the same as "od" on a prescription?
Both "sid" and "od" are prescription abbreviations that can indicate a medicine is taken once daily, though conventions vary between prescribers and pharmacies. Patients should confirm the exact dosing schedule with their pharmacist if an abbreviation is unclear.
