dat-, dos-, dot-, dow-, don-, dit-

(Greek + Latin: dare, to give, a giving, given; a gift; to grant, to offer)

Do ut des. (Latin)
Translation: "I give that you may give."

A reciprocal agreement or concession: The agreement which the lawyer drew up was tagged as Do ut des for purposes of filing with the courts.

donate (verb), donates; donated; donating
To give, to present, or to pledge something to an individual or to an organization, often in the context of charity and good will: The manufacturing giant agreed to donate 1,000 computers to the overseas project of the local educational organization.
donation (s) (noun), donations (pl)
A voluntary gift or contribution to a charity or cause: Jill often makes a donation of canned food to the local Food Bank or the local food distribution center to give to the homeless street people.
donative (s) (noun), donatives (pl)
A gift for a special or exceptional purpose: The hospital issued a call to its volunteers, urging them to consider making a generous donative to the children's toy fund.
donative (adjective), more donative, most donative
Descriptive of a gift or a gesture which is given freely without obligations: The donative nature of the time that the volunteers give to the overall functioning of the theater should not be under estimated.
donee (s) (noun), donees (pl)
A beneficiary or a recipient of a gift, money, or other benefits: "The theater was the donee of 8,000 hours of volunteer time this year which helped to sustain its productions."
donor (s) (noun), donors (pl)
A philanthropist or an individual who gives a contribution of financial aid or other benefits: "Mr. Jason was the primary donor to the fund to rebuild the art gallery after the fire."
doromania (s) (noun), doromanias (pl)
A psychiatric description of the urge or compulsion to give presents: "The wealthy philanthropist often disguised himself and, suffering from doromania, wandered the streets giving away money; especially, to those who were homeless."
doromaniac (s) (noun), doromaniacs (pl)
An individual who is prone to excessively give away gifts to strangers can be considered a mental health issue: "The doromanic was carefully observed by the Volunteer Street Patrol to be sure that he was safe when he went out on the streets distributing free food and money."
Dorothea (s) (noun)
A woman’s name, taken from the Greek meaning "a gift from God": "The heroine, Dorothea, lived up to her name and was kind and gentle to all who knew her."
Dorothy (s) (noun)
The English interpretation of a woman’s name taken from the Greek meaning gift from God: "In The Wizard of Oz, the heroine’s name is Dorothy who took her dog, Toto, with her during her adventures."
dosage (s) (noun), dosages (pl)
1. The amount of a therapeutic medication, or other substance, that is administered in a prescribed and measured amount at any one time: "The dosage was clearly indicated on the label of the medicine bottle."
2. In wine making terminology, the addition of sugar to specific wines: "The wine taster determined a slight dosage of sugar would be appropriate to add to the wine before corking."
3. Etymology: from Middle French (about 1400-1600) dose, from Late Latin dosis which came from Greek dosis, "a portion prescribed"; literally, "a giving".

Used by Galen and other Greek physicians to mean "an amount of medicine", from Greek didonai, "to give".

dose (s) (noun), doses (pl)
1. A measured quantity of medication administered once or at specific intervals; such as, a specified amount of medication to be taken at certain times: "The patient was very compliant with the doctor’s prescription to take the dose of medication three times each day."
2. The amount of radiation to which someone or something is exposed during a specific time, either accidentally or as part of an experiment or medical treatment: "Years ago many children were exposed to a low dose of radiation when using radiation machines which were available in shoe stores to help determine the proper fit of shoes."
3. An additional ingredient; such as, syrup or other sugary substance added to wine to fortify it: "The flavour of the wine was enhanced by a small dose of sugar that was added during the fermentation process."
4. Amounts, especially of unpleasant things, to which a person is subjected: "Manfred suffered many doses of bad luck."
5. The amount given at one time of a therapeutic drug, diagnostic agent, or radioactivity: "The doctor prescribed three doses of medicine each day for five days to aid in the healing of Dina's bronchitis."
6. Etymology: borrowed from Middle French dose which was borrowed from Late Latin dosis; from Greek dosis, "a portion prescribed"; literally, "a giving" from didonai, "to give".
dose (verb), doses; dosed; dosing
1. Giving or prescribing medicine in specified amounts: "The doctor provided a prescription for dosing the patient with some experimental medication."
2. Treating with an application or agent: "Madeline was dosing her feet with a salt and hot water mixture to ease the pain of her blisters."
dosimeter (s) (noun), dosemeters (pl)
1. An instrument that measures and indicates the amount of x-rays or radiation absorbed in a given period: "During the patient’s treatment, the nurse carefully read and recorded the results of the therapy from the dosimeter."
2. A device carried by a person for measuring the quantity of ionizing radiation; such as, gamma rays, to which one has been exposed: "Part of the hospital experiment was to have the patients wearing a dosimeter for three weeks and then submitting to tests at the end of the period."

Pointing to a page about doses and medical dosage Another term used for medical dosage can be seen at this posology page.