Learn English – Common root of “practice,” “practical,” and “practicum”

The formation of verbs in many Indo-European languages follows the following rule

    prefix + root verb

Examples

• English incoming, outgoing
• German einkommen (income), ausgehend (outgoing)
• Latin inīre (to come in), exīre (to go out)

German for instance still follows this system very closely and has a small number of ubiquitous prefixes which fall into two categories:

1. The so called separable¹ prefixes (ab- "off", an- "on", auf- "up", aus- "out", ein- "in" etc.), which indicate an ongoing action, a movement or a direction.
2. And the so called inseparable¹ prefixes: (be- (be), ent-, er-, ge-, mis-, ver- and zer-) which indicate a completed action (differentiated according to the type of outcome: neutral, successful, failed...).

The English be- prefix is clearly the same as the German be- and is therefore a remnant of its Germanic ascendancy.

It is actually of the same origin as the verb to be which linguists have traced back, through Proto Germanic to the reconstituted Proto Indo European root *bheu-, *bhu- meaning "to grow", "to turn into" or " to become"².

Ultimately most of the English words starting with a "be-" can be traced back to this notion of "to turn into"³.

The general form is:
   be + [quality]
and the corresponding meaning is:
   to turn into + [quality].

Let's illustrate all this theory with a few simple examples:

• to befriend somebody => to turn somebody into a friend.
• to beget something => to make something supplied, produced.
• to besot somebody (besotted) => to turn somebody into a sot (a dummy).
• to bewitch somebody => to make somebody possessed by a spell.
• to bedazzle somebody => to make him confused (see also bewilder)

These ones are slightly more difficult:

• to behold: the original meaning of to hold (OE healdan, German halten) is to keep. But to keep by actually keeping an eye on, to watch over. => So to behold is to make something watched.
• to bedevil someone => to make someone feel like in Hell.
• to believe something => to make something dear (loved). See also German glauben (ge + lieben) as well as Dutch geloven.
• to belong to someone => to make something go along with somebody.

As usual there are a few exceptions or look-alikes that don't fit into the template

• to behead => sometimes the "be" is categorised as privative but you can also interpret it as "turn into a head (and not much else)". The question being what do you sever: the head or the body ?
• between. It is not a verb. The "be" is akin to "by" and the "tween" part is akin to "two".

But their existence is not sufficient to belie the general theory outlined above.

The word autopsy is older, and had the original meaning "to see with one's own eyes". The Oxford English Dictionary writes that it was first used in a now-obsolete sense in the 1600s:

The action or process of seeing with one's own eyes; personal observation, inspection, or experience. Now rare.

Its current use only dates from the 1800s:

Med. Examination of the organs of a dead body in order to determine the cause of death, nature and extent of disease, result of treatment, etc.; post-mortem examination; an instance of this.

1805 Philos. Mag. 21 240 The distinguishing signs of peripneumony and pleurisy are so uncertain that they have been doubted by some celebrated physicians; they have been so often belied by cadaverous autopsia.

Necropsy is a much more recent coinage, and dates from the 1800s:

1842 R. Dunglison Med. Lexicon (ed. 3) 470/2 Necropsy, autopsia cadaverica.

Note that in the example given, autopsy cadaverica and necropsy are synonymous. However, because an autopsy could have been the inspection of any body, it was used in the phrase "cadaverous autopsy" or "autopsia cadaverica". It seems that necropsy may have developed as a one-word term to describe the autopsy of a deceased person, though by the 1830s autopsy was being used on its own in its current sense:

1830 Foreign Rev. 5 502 Two days after the autopsy, which was performed immediately on the emperor's decease, the whole body turned yellow.

However, it can be argued that the 1830 example was really referring to an autopsy of a body in general, who happened to be deceased (as there is qualification within the sentence which refers to death). Then, the first use of autopsy on its own without such qualification would be in the 1880s:

1881 Times 22 Sept. 4/1 The physicians' autopsy [of President Garfield] shows the bullet to be nowhere near where it was supposed to be.

From this, I think that necropsy developed as a one-word synonym to cadaverous autopsy, and then over time autopsy came to be synonymous with necropsy.